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Blood Alcohol Calculator
Estimate your blood alcohol content (BAC) based on drinks, weight, gender, and time elapsed.
Blood Alcohol Content (BAC)
0.058%
Approaching Legal Limit - Impaired
Estimated time to reach 0.00%: 3.9 hours
Disclaimer: This is an estimate only. BAC varies based on metabolism, food intake, medications, and other factors. Never drive after drinking. This tool is for educational purposes only.
Why Use Our Blood Alcohol Calculator?
Widmark Formula
Uses the scientific Widmark formula, the standard method for estimating blood alcohol content from weight and alcohol consumed.
Gender-Adjusted Calculation
Applies separate distribution factors for male and female as the Widmark formula specifies different body water ratios.
Drink Type Selection
Choose from beer, wine, or a shot - each representing one standard drink at 14 grams of pure alcohol.
Hours Elapsed Factor
Accounts for alcohol metabolism over time by subtracting approximately 0.015% BAC per hour elapsed.
Legal Status Indicator
Clearly labels whether the estimated BAC is below, approaching, or over the 0.08% legal driving limit.
Metric and Imperial Weight
Enter weight in kilograms or pounds. Switch units with one click.
Frequently Asked Questions
What is BAC?
Blood Alcohol Content (BAC) is the percentage of alcohol in your bloodstream. A BAC of 0.08% is the legal driving limit in most US states.
What is one standard drink?
One standard drink contains 14 grams of pure alcohol - equivalent to 12oz of regular beer (5%), 5oz of wine (12%), or 1.5oz of 40% spirits.
How is BAC calculated?
The calculator uses the Widmark formula: alcohol consumed in grams divided by (body weight in grams times the distribution factor) times 100, then subtracts alcohol metabolized over time.
How long does it take to sober up?
On average, the body eliminates about 0.015% BAC per hour. The calculator shows the estimated hours until your BAC reaches 0.00%.
Is this BAC calculator accurate?
It provides an estimate. Actual BAC varies with metabolism, food intake, medications, hydration, and tolerance. Never rely on any calculator to determine if you are safe to drive.
Is the BAC calculator free?
Yes. Completely free with no sign-up required.
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